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<script>

  /* 
  请封装一个函数,可以按照以下调用的方式进行求和
    - add(1,2,3)
    - add(1,2)(3)
    - add(1)(2,3)
    - add(1)(2)(3)
    - add(1,2)(2,2)(3,2)....
*/

  function add(part1, part2) {

    let sum = part1 + part2
    return add()

  }

  add(1, 2)(2, 2)(3, 2)



</script>

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